JP2010026467A - Display device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device and electronic equipment that sufficiently block external light to a reference light receiving element, reduce an influence of noise, and improve the SN ratio of a light reception system. <P>SOLUTION: The display device has a first optical sensor unit 31 which includes a light receiving element 311 and detects the intensity of external light in a display area, a second optical sensor unit 32 which has a light shield film CTL321 disposed in an optical path to the light receiving element 321, and a signal processing function of performing a difference processing between a detection signal of the first optical sensor unit 31 and a detection signal of the second optical sensor unit 32. The light shield film CTL321 is formed of a material same as that of a metal film for wiring. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device and an electronic apparatus provided with an optical sensor on a display pixel portion or a frame.

A technique is known that detects the illuminance of external light with a photosensor, thereby increasing the screen brightness when the ambient illuminance is bright and decreasing the screen brightness when the ambient illuminance is dark.
This technology not only makes the screen easier to see, but also reduces the power consumption of the backlight system when it is displayed by a backlight system such as a liquid crystal display device. Can contribute to battery life. For this reason, various techniques of this kind have been studied.

Several techniques have been proposed in which the display device itself is provided with a coordinate input function.
Specifically, for example, a display device using a pressure-sensitive touch panel (see Patent Documents 1 and 2), a display device using an electromagnetic induction touch panel system (see Patent Document 3), and the like are known.

However, it is difficult to reduce the size of the display device with the coordinate input function as described above, and there is a problem that the cost becomes higher than that of a normal display device.
Therefore, in recent years, in order to solve the above-described problem, a display device for identifying a coordinate in the display device by providing a light receiving element in each pixel of the display device and detecting incident light to the light receiving element has been actively developed. (See Patent Documents 4 and 5).

As described above, the device that enables the coordinate input in the display device by providing the light receiving element has only the advantage that the size can be reduced and the cost can be reduced as compared with the display device provided with the coordinate input function. In addition, multipoint coordinate input and area input are also possible.
JP 2002-149085 A JP 2002-41244 A JP-A-11-134105 JP 2004-318067 A JP 2004-318819 A

  By the way, in this type of display device, various characteristic drifts of the optical sensor are canceled. Therefore, there is a method of canceling the characteristic drift by arranging a reference light receiving element having the same structure as the optical sensor at a position where no light is irradiated and taking a difference between the output of the optical sensor and the reference element. Has been proposed.

  The light receiving element for reference (light sensor) needs to sufficiently shield the light from the outside, but until now, stray light entering from the inside of the cell has been incident on the element to the extent that the black color filter is placed, It was a cause of noise.

  The present invention provides a display device and an electronic device that can sufficiently block light from the outside to the reference light receiving element, can reduce the influence of noise, and can improve the SN ratio of the light receiving system. There is.

  A display device according to a first aspect of the present invention includes a light receiving element, includes a first light sensor unit that detects the intensity of external light in the display region, and a light receiving element, and a light shielding film is provided in an optical path to the light receiving element. A second photosensor unit disposed; and a signal processing unit that performs differential processing between a detection signal of the first photosensor unit and a detection signal of the second photosensor unit, and the light shielding film Is formed of a member in the same layer as the layer including the light shielding function.

  Preferably, the second photosensor section has a structure in which the light receiving element is formed of a thin film transistor or a PIN diode, and an electrode is connected to an upper wiring layer, and the light shielding film is formed of the upper wiring. The same layer is formed of the same member.

  Preferably, a backlight for irradiating display light to the display region is provided, and the gate electrode of the thin film transistor or the PIN diode is formed on the backlight side from the light receiving portion of the light receiving element and has a light shielding function.

  Preferably, the surface luminance of the display area can be changed, and the signal processing unit changes the surface luminance of the display unit according to the difference signal processing result.

  Preferably, a backlight for irradiating the display area with display light is provided, and the signal processing unit controls the level of display light by the backlight.

  Preferably, the first photosensor unit is capable of detecting reflected light from an object, and the signal processing unit is configured to detect the detection signal of the first photosensor unit and the detection of the second photosensor unit. A signal indicating whether or not there is an object in the first optical sensor unit is output based on a difference processing result with the signal.

  According to a second aspect of the present invention, there is provided an electronic apparatus having a display device, wherein the display device includes a light receiving element, and includes a first light sensor unit that detects the intensity of external light in the display region, and a light receiving element. A second optical sensor unit including a light-shielding film in the optical path to the light receiving element, and a differential process between the detection signal of the first optical sensor unit and the detection signal of the second optical sensor unit. The light shielding film is formed of a member in the same layer as the layer including a light shielding function.

  According to the present invention, external light is shielded by the light shielding film of the second photosensor unit. Then, in the signal processing unit, differential processing is performed on the detection signal of the first optical sensor unit and the detection signal of the second optical sensor unit. The signal resulting from the processing is a signal in which the influence of reflection noise in the first optical sensor unit, dark current at the time of light shielding, and offset noise is minimized.

  According to the present invention, light from the outside to the reference light receiving element can be sufficiently shielded, the influence of noise can be reduced, and the SN ratio of the light receiving system can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a configuration example of a liquid crystal display device according to an embodiment of the present invention.
2A to 2C are diagrams illustrating a configuration example of an effective display area portion in the liquid crystal display device of FIG. 2, in which FIG. 2A shows a matrix arrangement of cells, and FIG. FIG. 2C is a plan view and FIG. 2C is a cross-sectional view.
FIG. 3 is a diagram illustrating a configuration example of the photodetector circuit according to the present embodiment.

  As shown in FIG. 1, the liquid crystal display device 1 includes an effective display area unit (image display unit) 2 as a display unit, a light detection unit (LDTC) 3, a vertical drive circuit (VDRV) 4, and a horizontal drive circuit (HDRV). 5 and a signal processing circuit (SPRC) 6.

  The liquid crystal display device 1 of the present embodiment is configured to be able to change the surface luminance of the effective display area 2 according to the intensity (illuminance) of outside light (actually, the light emission intensity of the backlight 25 can be changed). Yes. That is, the liquid crystal display device 1 of the present embodiment has a light control function, for example.

In the effective display area portion 2, a plurality of display cells 21 including display circuits 210 that form display pixels are arranged in a matrix. The effective display area 2 forms a display screen.
The light detection unit 3 is disposed adjacent to (in close proximity to) the effective display region unit 2.
The light detector 3 may be formed integrally with the effective display area 2 instead of being formed adjacent to the outside of the effective display area 2 (non-display area outside the effective area of the display area). Is possible.

  As shown in FIG. 3, the light detection unit 3 includes a first light sensor unit 31, a second light sensor unit 32, a reset switch 33, a comparator 34, and a capacitor C31.

The first optical sensor unit 31 includes a light receiving element (photosensor, optical sensor) 311 and detects the intensity of external light in the effective display region unit 2.
The second optical sensor unit 32 includes a light receiving element 321, and a light shielding film CTL 321 formed on the same metal (for example, Al) as wiring is disposed on the optical path to the light receiving element 321. It is configured to sufficiently shield the light from.
Note that the light-shielding film is not limited to the wiring layer, and can be formed of a light-shielding film on the metal layer of the pixel electrode or another TFT substrate side.

  The first optical sensor unit 31 and the second optical sensor unit 32 can detect the external light level by receiving external light, for example, without a light-shielding object (for example, a user's finger) held over the upper part. It is arranged in the area.

In the light detection unit 3 of FIG. 3, the light sensor 311 of the first light sensor unit 31 and the light-shielding side sensor 321 of the second light sensor unit 32 are connected to the power supply potential VDD and the reference potential VSS (for example, the ground potential GND). Are connected in series in the immediate vicinity (close to each other).
Then, the light detection unit 3 is a signal obtained by removing the detection current component (for example, dark current component) of the light shielding side sensor 321 of the second photosensor unit 32 from the detection current component of the photosensor 311 of the first photosensor unit 31. Is compared with a reference voltage using the comparator 34 to obtain an external light intensity signal. The light detection unit 3 outputs the obtained signal to the signal processing circuit 6 as a detection signal S3.
In the detection signal S3 from the light detection unit 3, the detection component in the infrared region detected by the optical sensor 311 is removed.
Thus, the light detection unit 3 has a function as a signal processing unit that performs a difference process between the detection signal of the first optical sensor unit and the detection signal of the second optical sensor unit.

And the signal processing circuit 6 controls the light quantity given to the effective display area | region part 2 according to detection signal S3 by the photon detection part 3, for example.
In the present embodiment, the signal processing circuit 6 changes the surface luminance of the effective display area part (screen display part) 2 by the control signal CTL according to the output level of the detection signal S3 of the light detection part 3.

Returning to the description of the effective display area 2.
For example, in a predetermined area of the effective display area 2, an R display cell 21R, a G display cell 21G, and a B display cell 21B corresponding to the three primary colors are arranged from the left in FIG. This arrangement is repeated through a light shielding mask (black mask) (not shown) or without a black mask.

  In the effective display area 2, as shown in FIG. 2B, the R color filter FLT-R is arranged in the arrangement area of the R display cell 21R, and the G arrangement is arranged in the arrangement area of the G display cell 21G. A B color filter FLT-B is formed in the arrangement region of the color filter FLT-G and the B color display cell 21B.

In the effective display area 2, as shown in FIG. 2C, a liquid crystal layer 24 is interposed between a TFT substrate (first transparent substrate) 22 and a counter substrate (second transparent substrate) 23 formed of glass, for example. Is enclosed and formed. Further, for example, a backlight 25 is disposed on the bottom surface 221 side of the TFT substrate 22.
The display circuit 210 of each display cell 21 is formed on the base surface 222 side of the TFT substrate 22.
On the other hand, various filters FLT-R, FLT-G, and FLT-B are formed on the base surface 231 of the counter substrate 23.

As shown in FIG. 2A, the display circuit 210 in each display cell 21 includes a thin film transistor (TFT) 211 as a switching element.
The display circuit 210 includes a liquid crystal cell (LC) 212 in which a pixel electrode is connected to the drain electrode (or source electrode) of the TFT 211, and a storage capacitor (Cs) 213 in which one electrode is connected to the drain electrode of the TFT 211. Has been.

For each of these display cells 21, scanning lines (gate lines) 7-1 to 7-m are wired along the pixel arrangement direction for each row, and display signal lines 8-1 to 8-n are arranged for each column. Are wired along the pixel array direction.
The gate electrode of the TFT 211 of each display cell 21 is connected to the same scanning line (gate line) 7-1 to 7-m in each row unit. Further, the source electrode (or drain electrode) of the TFT 211 of each display cell 21 is connected to the same display signal line 8-1 to 8-n for each column.

In the configuration of FIG. 2A, the scanning lines 7-1 to 7-m are connected to and driven by the vertical drive circuit 4.
Further, the wired display signal lines 8-1 to 8-n corresponding to the display cells 21 are connected to the horizontal drive circuit 5 and driven by the horizontal drive circuit 5.

Further, in a general liquid crystal display device, pixel storage capacitor lines (Cs) 9-1 to 9-m are independently wired, and between the pixel storage capacitor lines 9-1 to 9-m and connection electrodes. A storage capacitor 213 is formed.
For example, a predetermined DC voltage is applied as a common voltage VCOM to the counter electrode of the liquid crystal cell 212 of the display cell 21 of each pixel unit 20 and / or the other electrode of the storage capacitor 213 through a common wiring (common wiring).
Alternatively, a common voltage VCOM whose polarity is inverted every horizontal scanning period (1H) is applied to the counter electrode of the liquid crystal cell 212 of each display cell 21 and the other electrode of the storage capacitor 213, for example.

The vertical drive circuit 4 receives a vertical start signal VST, a vertical clock VCK, and an enable signal ENB generated by a clock generator (not shown) and scans in the vertical direction (row direction) every field period. Then, the vertical drive circuit 4 performs a process of sequentially selecting each display cell 21 connected to the scanning lines 7-1 to 7-m in units of rows.
That is, when the scanning pulse SP1 is applied to the scanning line 7-1 from the vertical drive circuit 4, the pixels in each column of the first row are selected, and the scanning pulse SP2 is applied to the scanning line 7-2. In this case, the pixels in each column of the second row are selected. Similarly, scanning pulses SP3,..., SPm are sequentially applied to the scanning lines 7-3,.

The horizontal driving circuit 5 generates a sampling pulse in response to a horizontal start pulse HST for instructing the start of horizontal scanning generated by a clock generator (not shown) and a horizontal clock HCK having mutually opposite phases as a reference for horizontal scanning.
The input image data R (red), G (green), and B (blue) are sequentially sampled in response to the generated sampling pulse, and each display signal line 8 serves as a data signal to be written to each display cell 21. -1 to 8-n.

  Below, the structure of the 1st optical sensor part 31 in the optical detection part 3 and the 2nd optical sensor part 32 is demonstrated in detail.

  FIG. 4 is a cross-sectional view showing a structural example in which photosensors (light receiving elements) of the first optical sensor unit and the second optical sensor unit are formed by TFTs.

A gate electrode 332 covered with a gate insulating film 331 is formed on the TFT substrate 22 (transparent insulating substrate such as a glass substrate). The gate electrode is formed, for example, by depositing a metal or alloy such as molybdenum (Mo) or tantalum (Ta) by a method such as sputtering.
A semiconductor film (I layer, channel formation region) 333 and a pair of n ⁺ diffusion layers 334 and 335 (source and drain regions) are formed on the gate insulating film 331 with the semiconductor film 333 interposed therebetween.
Further, an interlayer insulating film 336 is formed so as to cover the gate insulating film 331, the semiconductor layer (channel formation region) 333, and the n ⁺ diffusion layers 334 and 335 (source and drain regions). The interlayer insulating film 336 is formed of, for example, SiN, SiO ₂ or the like.
A source electrode 338 is connected to one n ⁺ diffusion layer 334 via a contact hole 337 a formed in the interlayer insulating film 336, and a contact formed in the interlayer insulating film 336 is connected to the other n ⁺ diffusion layer 335. A drain electrode 339 is connected through the hole 337b.
The source electrode 338 and the drain electrode 339 are formed by patterning, for example, aluminum (Al).
A planarization film 340 is formed over the interlayer insulating film 336, the source electrode 338, and the drain electrode 339.
For example, in the case where it is arranged in the effective display area or the non-display area of the display area portion, the liquid crystal layer 24 is formed on the planarizing film 349.

In the present embodiment, for example, as shown in FIG. 4, the incident light path of the external light of the second photosensor unit 32 is shielded from Al used for wiring on the I layer 333 that is the light receiving unit. A film 350 is formed and configured to shield stray light from the outside.
For reference, a plan view of the second photosensor unit 32 is shown in FIG.

  Hereinafter, a method for forming the second photosensor portion having the light shielding film in the same layer as the wiring according to the present embodiment will be described with reference to FIGS. 6 (A) to (G) and FIGS. 7 (H) to (K). To do.

As shown in FIGS. 6A and 6B, a gate electrode 401 is formed on a glass substrate 22, and a gate insulating film 402 is formed thereon by a CVD apparatus. The gate insulating film 402 has a laminated structure and is a SiN or SiO ₂ film from the glass substrate 22 side.
Next, as shown in FIG. 6D, an amorphous silicon 403 is formed on the gate insulating film 402 and then irradiated with an excimer laser (laser annealing) to polycrystallize the silicon film.
Next, impurities are implanted into the polycrystalline silicon film by an ion implanter in order to control the threshold value of the transistor. Then, as shown in FIG. 6 (E), the upper part of the polycrystalline silicon film 404 for forming the SiO ₂ film 405 by the CVD apparatus.
Thereafter, a resist is patterned on the SiO ₂ film by photolithography, and anodes and cathodes are formed by an ion implanter as shown in FIG.
Thereafter, after removing the resist, the substrate is placed in an annealing furnace to activate the impurities.
Next, as shown in FIG. 6G, a resist pattern is formed again, and the polycrystalline silicon film and SiO ₂ are patterned by a dry etcher.
Next, as shown in FIG. 7H, a SiO ₂ , SiN, and SiO ₂ film, which is an interlayer insulating film 406, is formed by a CVD apparatus, and dangling bonds in the polycrystalline silicon are formed by hydrogen in an annealing furnace. Terminate.
Next, as shown in FIG. 7I, a resist is patterned by photolithography, and contact holes 407 are formed in the source and drain portions of polycrystalline silicon and gate electrodes by etching.
After that, as shown in FIG. 7 (J), an Al 408 to be a signal wiring is formed and patterned by photolithography and etching as shown in FIG. 7 (K).

In the above description, an example in which the light receiving element of the optical sensor unit is formed by a TFT is shown. However, the light receiving element is not limited to a TFT, and is formed by a PIN diode having a structure as shown in FIGS. It is also possible.
For ease of understanding, the same components as those in FIGS. 4 and 5 are denoted by the same reference numerals.
The difference is that an anode electrode 342 is formed instead of the p ⁺ diffusion layer 341 instead of the n ⁺ diffusion layer 334, and a cathode electrode 344 is formed instead of the drain electrode.

In the light detection section 3 having the above configuration, the light sensor 311 of the first light sensor section 31 and the light-shielding side sensor 321 of the second light sensor section 32 are connected to the power supply potential VDD and the reference potential VSS (for example, ground potential). GND) is connected in series (closely) in series.
In the light detection unit 3, external light applied to the effective display region unit 2 is received by the photosensor 311 of the first photosensor unit 31.
The light detection unit 3 is a signal obtained by removing the dark current component, which is the detection current component of the light shielding side sensor 321 of the second photosensor unit 32, from the detection current component of the photosensor 311 of the first photosensor unit 31. Is compared with the reference voltage using the comparator 34. The comparison result is obtained as an external light intensity signal and is output to the signal processing circuit 6 as a detection signal S3.
In the detection signal S3 from the light detection unit 3, the detection component in the infrared region detected by the optical sensor 311 is removed.
Then, the signal processing circuit 6 changes the surface luminance of the effective display area part (screen display part) 2 by the control signal CTL according to the output level of the detection signal S3 of the light detection part 3.
For example, the level of display light from the backlight 25 is controlled.

Instead of forming the light detection unit 3 adjacent to the outside of the effective display region unit 2 (the non-display region unit outside the effective region of the display region unit), as shown in FIG. It is also possible to form it integrally.
Since other configurations and functions are basically the same as those of the above-described embodiment, detailed description thereof will be omitted.

In the above description, the dimming function capable of changing the surface brightness of the effective display area portions 2, 2 </ b> A, 2 </ b> B according to the intensity (illuminance) of outside light (actually, the emission intensity of the backlight 25 can be changed) A liquid crystal display device having the above has been described.
The present invention is not limited to the dimming function, and can also be applied to a backlight reflected light detection system as shown in FIG.

As described above, according to the present embodiment, the light detection unit 3 includes the light receiving element 311 and detects the intensity of external light in the display area, and the light path to the light receiving element 321. A second optical sensor unit 32 on which a light shielding film CTL321 is disposed.
The light shielding film CTL321 is formed of the same layer as the signal wiring, and has a function of removing at least a component corresponding to the dark current component detected by the second photosensor unit 32 from the output of the first photosensor unit 31. Therefore, the following effects can be obtained.

That is, according to the present embodiment, the light from the outside to the light receiving element of the second reference optical sensor unit 32 can be sufficiently shielded, the influence of noise can be reduced, and the SN ratio of the light receiving system is improved. can do.
In addition, the influence of noise can be reduced without requiring a calibration operation when the power is turned on, and the SN ratio of the light receiving system can be improved.

In the system using the backlight or the external light imaging system, the offset noise of the light receiving element (photo sensor) and the pixel circuit can be removed, so that a high SN ratio can be realized.
Since the interference noise from the display can be removed in the system using the backlight or the external light imaging system, a high SN ratio can be realized.
Since the above noise can be canceled in real time, a highly reliable system that is resistant to temperature characteristics and time fluctuations can be realized.
For the same reason as described above, the calibration operation at the time of turning on the power becomes unnecessary.

It should be noted that one light receiving element may be arranged for a plurality of pixels, one light receiving element may be arranged for each of RGB, and one light receiving element is arranged for one pixel. It does not matter.
The arrangement of the light receiving elements in the display device when the present invention is applied is not particularly mentioned. In this way, by applying the present invention to a display device with a built-in light receiving element, it is possible to use a light receiving signal with little influence of noise in post-processing. Further, light reception (imaging) can be performed while preventing the display-side signal from being mixed into the imaging-side signal.

The display device according to the present embodiment includes a flat module-shaped display as shown in FIG.
For example, a pixel array portion in which pixels made up of a liquid crystal element, a thin film transistor, a thin film capacitor, a light receiving element, and the like are integrated and formed in a matrix on an insulating substrate 22 is provided. An adhesive is disposed so as to surround the pixel array portion (pixel matrix portion), and a counter substrate such as glass is attached to form a display module.
The transparent counter substrate 23 may be provided with a color filter, a protective film, a light shielding film, and the like as necessary. In the display module, for example, an FPC (flexible printed circuit) may be provided as a connector CNT for inputting / outputting a signal to / from the pixel array unit from the outside.

The display device according to the present embodiment described above can be applied to various electronic devices shown in FIGS. 12 to 16, for example, a digital camera, a notebook personal computer, a mobile terminal device such as a mobile phone, and a video camera. . The present invention can be applied to display devices of electronic devices in various fields that display video signals input to these electronic devices or video signals generated in the electronic devices as images or videos.
Below, an example of the electronic device to which this embodiment is applied is demonstrated.

FIG. 12 is a perspective view showing a television to which the present embodiment is applied.
The television 500 according to this application example includes a video display screen unit 510 including a front panel 520, a filter glass 530, and the like, and is manufactured by using the display device according to the present embodiment as the video display screen unit 510. The

FIG. 13 is a perspective view showing a digital camera to which the present embodiment is applied. FIG. 13A is a perspective view seen from the front side, and FIG. 13B is a perspective view seen from the back side.
The digital camera 500A according to this application example includes a flash light emitting unit 511, a display unit 512, a menu switch 513, a shutter button 514, and the like, and is manufactured by using the display device according to this embodiment as the display unit 512. The

FIG. 14 is a perspective view showing a notebook personal computer to which the present embodiment is applied.
A notebook personal computer 500B according to this application example includes a main body 521 including a keyboard 522 operated when inputting characters and the like, a display unit 523 for displaying an image, and the like. It is produced by using an apparatus.

FIG. 15 is a perspective view showing a video camera to which the present embodiment is applied.
A video camera 500C according to this application example includes a main body portion 531, a subject photographing lens 532, a start / stop switch 533 at the time of photographing, a display portion 534, and the like on the side facing forward. It is manufactured by using the display device according to the embodiment.

FIG. 16 is a view showing a mobile terminal device to which the present embodiment is applied, for example, a mobile phone. FIG. 16 (A) is a front view in an opened state, FIG. 16 (B) is a side view thereof, FIG. 16C is a front view in a closed state, FIG. 16D is a left side view, FIG. 16E is a right side view, FIG. 16F is a top view, and FIG. is there.
A cellular phone 500D according to this application example includes an upper housing 541, a lower housing 542, a connecting portion (here, a hinge portion) 543, a display 544, a sub display 545, a picture light 546, a camera 547, and the like. The cellular phone 500 </ b> D is manufactured by using the display device according to the present embodiment as the display 544 and the sub display 545.

  In addition, the display device according to the present embodiment can be applied to the following display imaging device. In addition, the display imaging device can be applied to the various electronic devices described above.

FIG. 17 is a diagram illustrating an overall configuration of the display imaging apparatus.
The display imaging apparatus 1000 includes an I / O display panel 2000, a backlight 1500, a display drive circuit 1200, a light receiving drive circuit 1300, an image processing unit 1400, and an application program execution unit 1100. .

The I / O display panel 2000 has a liquid crystal panel (LCD (Liquid Crystal Display)) in which a plurality of pixels are arranged in a matrix over the entire surface, and predetermined graphics and characters based on display data while performing line sequential operation. This includes a function (display function) for displaying the images. The I / O display panel 2000 has a function (imaging function) for imaging an object in contact with or close to the I / O display 2000 as described later.
The backlight 1500 is a light source of the I / O display panel 2000 in which a plurality of light emitting diodes are arranged, for example. The backlight 1500 performs an on / off operation at a high speed at a predetermined timing synchronized with the operation timing of the I / O display 2000 as described later.

  The display drive circuit 1200 drives the I / O display panel 2000 so that an image based on the display data is displayed on the I / O display panel 2000 (so as to perform a display operation) (line-sequential operation). Drive circuit).

  The light receiving drive circuit 1300 is a circuit that drives the I / O display panel 2000 (drives line-sequential operation) so that light reception data can be obtained in the I / O display panel 2000 (so as to image an object). It is. The light reception data at each pixel is accumulated in the frame memory 1300A, for example, in units of frames, and is output to the image processing unit 14 as a captured image.

  The image processing unit 1400 performs predetermined image processing (calculation processing) based on the captured image output from the light receiving drive circuit 1300. The image processing unit 1400 detects and acquires information related to an object in contact with or close to the I / O display 2000 (position coordinate data, data related to the shape and size of the object, etc.). The details of the detection process will be described later.

The application program execution unit 1100 executes processing according to predetermined application software based on the detection result by the image processing unit 1400. In this case, for example, the display data includes the position coordinates of the detected object and displayed on the I / O display panel 2000.
The display data generated by the application program execution unit 1100 is supplied to the display drive circuit 1200.

  Next, a detailed configuration example of the I / O display panel 2000 will be described with reference to FIG. The I / O display panel 2000 includes a display area (sensor area) 2100, a display H driver 2200, a display V driver 2300, a sensor readout H driver 2500, and a sensor V driver 2400. Yes.

  The display area (sensor area) 2100 is an area that modulates light from the backlight 1500 to emit display light and images an object that is in contact with or close to this area. A liquid crystal element that is a light emitting element (display element) and a light receiving element (imaging element) to be described later are arranged in a matrix.

  The display H driver 2200 line-sequentially drives the liquid crystal elements of each pixel in the display area 2100 together with the display V driver 2300 based on the display drive display signal and the control clock supplied from the display drive circuit 1200. Is.

  The sensor readout H driver 2500 drives the light receiving element of each pixel in the sensor area 2100 together with the sensor V driver 2400 to obtain a light reception signal.

  Next, a detailed configuration example of each pixel in the display area 2100 will be described with reference to FIG. A pixel 3100 shown in FIG. 19 includes a liquid crystal element as a display element and a light receiving element.

Specifically, on the display element side, a switching element 3100a made of a thin film transistor (TFT) or the like is disposed at the intersection of a gate electrode 3100h extending in the horizontal direction and a drain electrode 3100i extending in the vertical direction. Has been. Further, a pixel electrode 3100b including a liquid crystal is disposed between the switching element 3100a and the counter electrode.
Then, the switching element 3100a is turned on / off based on the drive signal supplied via the gate electrode 3100h, and the pixel voltage is applied to the pixel electrode 3100b based on the display signal supplied via the drain electrode 3100i in the on state. Is applied and the display state is set.

On the other hand, on the light receiving element side adjacent to the display element, a light receiving sensor 3100c made of, for example, a photodiode or the like is disposed, and the power supply voltage VDD is supplied.
Further, a reset switch 3100d and a capacitor 3100e are connected to the light receiving sensor 3100c, and charges corresponding to the amount of received light are accumulated in the capacitor 3100e while being reset by the reset switch 3100d.
The accumulated charge is supplied to the signal output electrode 3100j via the buffer amplifier 3100f at the timing when the readout switch 3100g is turned on, and is output to the outside.
The on / off operation of the reset switch 3100d is controlled by a signal supplied from the reset electrode 3100k, and the on / off operation of the readout switch 3100g is controlled by a signal supplied from the readout control electrode 3100k.

  Next, a connection relationship between each pixel in the display area 2100 and the sensor readout H driver 2500 will be described with reference to FIG. In the display area 2100, a red (R) pixel 3100, a green (G) pixel 3200, and a blue (B) pixel 3300 are arranged side by side.

The electric charges accumulated in the capacitors connected to the light receiving sensors 3100c, 3200c, 3300c of each pixel are amplified by the respective buffer amplifiers 3100f, 3200f, 3300f. Then, when the readout switches 3100g, 3200g, and 3300g are turned on, the readout switches 3100g, 3200g, and 3300g are supplied to the sensor readout H driver 2500 via the signal output electrodes.
Each signal output electrode is connected to a constant current source 4100a, 4100b, 4100c, and a signal corresponding to the amount of received light is detected by the sensor reading H driver 2500 with high sensitivity.

  Next, the operation of the display imaging device will be described in detail.

  First, a basic operation of the display imaging apparatus, that is, an image display operation and an object imaging operation will be described.

In this display imaging apparatus, a display drive signal is generated in the display drive circuit 1200 based on display data supplied from the application program execution unit 1100. With this drive signal, line-sequential display drive is performed on the I / O display 2000, and an image is displayed.
At this time, the backlight 1500 is also driven by the display drive circuit 1200, and is turned on / off in synchronization with the I / O display 2000.

  Here, the relationship between the on / off state of the backlight 1500 and the display state of the I / O display panel 2000 will be described with reference to FIG.

  First, for example, when an image is displayed with a frame period of 1/60 seconds, the backlight 1500 is turned off (turned off) in the first half of each frame period (1/120 seconds), and display is not performed. On the other hand, in the second half of each frame period, the backlight 1500 is turned on (turned on), a display signal is supplied to each pixel, and an image in that frame period is displayed.

  Thus, the first half period of each frame period is a non-light period in which display light is not emitted from the I / O display panel 2000, while the display light is emitted from the I / O display panel 2000 in the second half period of each frame period. It has become a light period.

  Here, when there is an object (for example, a fingertip) that is in contact with or close to the I / O display panel 2000, the light receiving element of each pixel in the I / O display panel 2000 is driven by line sequential light receiving drive by the light receiving drive circuit 1300. The object is imaged. Then, light reception signals from the respective light receiving elements are supplied to the light receiving drive circuit 1300. In the light receiving drive circuit 1300, the light receiving signals of the pixels for one frame are accumulated and output to the image processing unit 14 as a captured image.

  The image processing unit 1400 performs predetermined image processing (arithmetic processing) described below based on the captured image, and information (position coordinate data, object shape, and the like) related to an object in contact with or close to the I / O display 2000. Size data) is detected.

It is a block diagram which shows the structural example of the liquid crystal display device which concerns on embodiment of this invention. FIG. 2 is a diagram illustrating a configuration example of an effective pixel area in the liquid crystal display device of FIG. 1. It is a circuit diagram which shows the structural example of the photon detection part which concerns on this embodiment. It is sectional drawing which shows the structural example which formed the photo sensor (light receiving element) of the 1st optical sensor part and the 2nd optical sensor part with TFT. It is a top view of the 2nd photosensor part. It is FIG. 1 which shows a manufacturing process in the 2nd optical sensor part. It is FIG. 2 which shows a manufacturing process in the 2nd optical sensor part. It is a figure which shows the example which forms the light receiving element of an optical sensor part with a PIN diode. It is a block diagram which shows the other structural example of the liquid crystal display device which concerns on embodiment of this invention. It is a figure which shows typically the detection system of the reflected light of a backlight. It is a schematic diagram which shows the example of a flat type module shape. It is a perspective view which shows the television with which this embodiment is applied. It is a perspective view which shows the digital camera to which this embodiment is applied. It is a perspective view which shows the notebook type personal computer to which this embodiment is applied. It is a perspective view which shows the video camera to which this embodiment is applied. It is a figure which shows the portable terminal device to which this embodiment is applied, for example, a mobile telephone. It is a block diagram showing the structure of the display imaging device which concerns on embodiment of this invention. FIG. 18 is a block diagram illustrating a configuration example of an I / O display panel illustrated in FIG. 17. It is a circuit diagram showing the structural example of each pixel. It is a circuit diagram for demonstrating the connection relation of each pixel and the sensor reading H driver. It is a timing diagram for demonstrating the relationship between the ON / OFF state of a backlight, and a display state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A ... Liquid crystal display device, 2, 2A, 2B ... Effective display area part, 3, 3A ... Photodetection part, 4 ... Vertical drive circuit (VDRV), 5 ... Horizontal drive Circuit (HDRV), 6, 6A ... Signal processing circuit (SPRC), 11 ... Light reception signal line, 10 ... Light reception control circuit (RCTL), 12 ... First control line, 13 ... Second control line, 21... Display cell, 31... First photosensor unit, 32 .. second photosensor unit, 311, 321... Light receiving element (photosensor), CTL 321. ..Light shielding film

Claims (7)

A first optical sensor unit that includes a light receiving element and detects the intensity of external light in the display region;
A second optical sensor unit including a light receiving element and having a light shielding film disposed in an optical path to the light receiving element;
A signal processing unit that performs a difference process between the detection signal of the first photosensor unit and the detection signal of the second photosensor unit;
The light shielding film is
A display device formed by a member in the same layer as a layer including a light shielding function. The second photosensor unit is
The light receiving element is formed of a thin film transistor or a PIN diode,
The electrode has a structure connected to the upper wiring layer,
The display device according to claim 1, wherein the light shielding film is formed of the same member in the same layer as the upper wiring layer. A backlight for illuminating the display area with display light;
The display device according to claim 2, wherein a gate electrode of the thin film transistor or the PIN diode is formed on a backlight side from a light receiving portion of the light receiving element and has a light shielding function. The display area can change the surface brightness,
The signal processor is
The display device according to claim 2, wherein surface luminance of the display unit is changed according to the difference signal processing result. A backlight for illuminating the display area with display light;
The signal processor is
The display device according to claim 4, wherein a level of display light by the backlight is controlled. The first optical sensor unit includes:
The reflected light from the object can be detected,
The signal processor is
2. A signal indicating whether or not there is an object in the first optical sensor unit is output based on a difference processing result between the detection signal of the first optical sensor unit and the detection signal of the second optical sensor unit. The display device described. An electronic device having a display device,
The display device
A first optical sensor unit that includes a light receiving element and detects the intensity of external light in the display region;
A second optical sensor unit including a light receiving element and having a light shielding film disposed in an optical path to the light receiving element;
A signal processing unit that performs a difference process between the detection signal of the first photosensor unit and the detection signal of the second photosensor unit;
The light shielding film is
An electronic device formed of a member having the same layer as a layer including a light shielding function.

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